Effusion, joint

The accumulation of fluid in the space around a joint, resulting in limitation of movement, pain and tenderness, and swelling. All joints are enclosed by a capsule lined with a membrane called the synovium. The synovium usually secretes small amounts of fluid to lubricate the joint. But if the synovium is inflamed or damaged it produces excessive fluid.

The inflammation and pain can be relieves by analgesic drugs and nonsteroidal anti-inflammatory drugs and by having injections of corticosteroid drugs. The swelling often reduces if the affected joint is bandaged firmly, rested, cooled with ice packs and kept elevated. In some cases, the excess fluid is drawn out of the joint and needle.